How to get rid of headaches that can't be cured?

My girlfriend will get incurable headaches that will not go away unless she sleeps. Tylenol, Advil, any kind of pain reliever doesn't work. It makes me worry, could it be something wrong with her brain, not enough circulation flow, some kind of toxin in her body? She went to the doctor and was given muscle relaxers, they don't work either they just make her p out so when she wakes up they're gone. I tried searching on Google and found nothing. What the hell is going on?